Combined electrical and centrifugal gas cleaning apparatus



H. B. RUDER Feb. 2, 1932.

} COMBINED ELECTRICAL AND CENTRIFUGAL GAS CLEANING APPARATUS 2 Sheets-Sheet Filed Sept. 5, 1950 BY QQ/ ATTO EYS.

H. B. RUDER Feb. 2, 1932.

COMBINED ELECTRICAL AND CENTRIFUGAL GAS CLEANING APPARATUS Filed Sept. 5, 1930 2 Sheets-Sheet 2 w R mm n ATTO NYS.

Patented Feb. 2, 1932 TATES HEINRICH BNHAED mines, or :rnANxronr-on-rnn- 1...

: onaman'n, assrenoa 'ro ?ORATION @F CALH'ORNIA COMBINED ELECTRICAL AND CENTRIFUGAL GAS CLEANTITG APPATUS A Application filed September 5, 1980, Serial No. 479,997, and in Germany tctc'ner a, 19%.

This invention relates to apparatus for removing suspended particles from gases by the combined action of electrical precipitation and centrifugal force,'and particularly to gas cleaning apparatus in which the gas is caused to whirl by passing the same between opposing walls arranged in spiral or circular fashion, and in which discharge elec trodes are mounted in the space between said walls and an electric discharge from said discharge electrodes is maintained so as to simultaneously subject the suspended particles to the action of centrifugal force and the action of the electric discharge.

The principal object of this invention is to rovide an apparatus of the above type wh1ch will operate more efliciently than those heretofore used, and particularly an apparatus in which the optimum combination of the two separating actions is obtained.

In previous apparatus of this type the electric discharge from the discharge electrodes has been directed in part outwardly toward the wall outside the whirlinggases and in part inwardly toward the wall inside the whirling gases, and the electric field in this latter direction has opposed the action of centrifugal force. The suspended particles contained in the portion of the gases between the discharge electrodes and theouter wall have been precipitated outwardly both by centriiugal force and by electrical action, but the suspended particles in the portion of the as between the discharge electrodes and the mnerwall have been subjected to the electric field tending to drive them toward the inner wall and to the action of centrifugal force tending to drive them away from said inner wall. Furthermore, since the centrifugal force concentrates the major portion of the suspended particles in the outer portion of the gas stream, the inwardly directed electric discharge represents practically wasted energy.

An important object of this invention'is to cause the electric discharge to occur principally between the discharge electrodes and the outer wall of the spiral gas passage, thus utilizing the energy of the electric discharge to the best advantage. Not only is the electric discharge thus confined principally to the outer portion of the 'gas stream in which the concentration of the suspended particles is r: latively high, but furthermore such electric discharge acts in the same direction as the centrifugal force.

A further object is to permit the dischargdischarge electrode members disposed in said passage, and a source of electric current connected to said wall members and to said discharge electrode members and adapted to maintain an electric discharge from said discharge electrode members, said discharge electrode members having portions of relatively sharp surface curvature, such as points or edges, at their outer sides for facilitating electric discharge therefrom, and having their inner sides of relatively gradual curvature and free from sharp points or edges, so as to minimize electric discharge from said inner sides, and said discharge electrodes being preferably mounted with the discharging portions thereof at a greater distance from the wall outside the gas passage than from the wall inside the gas passage.

The accompanying drawings illustrate an H apparatus embodying my invention, and referring thereto:

Fig. 1 is a side elevation of such apparatus.

Fig. 2 is a horizontal section on line 22 in Fig. 1.

The apparatus is shown as comprising wall members 1 curved about a substantially vertical axisand defining a spiral gas passage 2. The outermost wall provides a housing for the apparatuspwhile the innermost wall encloses acentral space 3 which communicates with the inner end of the spiral gas passage through opening 4 in' said innermost wall. In the present case the gases are shown as delivered into the outer end of the spiral gas passage, by means of inlet flue 5 and connection 6, and withdrawn from the central space 3 by means of outlet flue 7, but it will of Collected material.

Within the spiral gas passage, and intermediate the walls 1, are suspended a plurality of discharge electrode members 11. Said members are shown as connected at their upper and lower ends to spiral rods or pipes 12 and 13 respectively. The upper support ing rod 12 is shown as suspended by means of vertical rods or'frame members 14 from transverse supporting bars 15 mounted on insulators 16. The frame-members 14 are shown as extending up through compartments 17 above the top wall of the apparatus, and are insulated by means of insulators 18 where they pass through the top walls of said compartments. The discharge electrode system above described may be connected by an electrical conductor indicated diagrammatically at 19 to the high tension side of a source of electric current at suitable potential, while the walls 1, which constitute the collecting electrodes, may be connected by a suitable conductor such as indicated diagrammatically at 21 to the low tension side of said source of current. Said collecting electrodes are also preferably electrically grounded as indicated at 22. Said source of current may be of any suitable type adapted to produce either unidirectional or alternating electric cylindrical or round in shape but provided with projecting fins or vanes 25 at one side,

current and to maintain a sufiicient potential difference between the electrodes to efiect electric discharge therebetween. The cur-' rent used may, for example, consist of unidirectional electric current produced by rectification of alternating current.

In accordance with this invention, the discharge electrode members 11* are shown as and are so mounted that the edges or points 26 of said fins or vanes are disposed at the outer sides of said discharge electrode members, thus providing portions of relatively sharp surface curvature disposed toward the wall outside the gas passage in which said discharge electrode members are mounted. The inner sides of the discharge electrode members, on the other hand, are of relatively gradualcurvature and free from sharp points or edges. Since electric discharge takes place much more easily from a sharp edge or other element of relatively great surfor electric discharge from the discharge electrodes toward the inner wall than toward 1 the outer wall. Consequently, the distance indicated at a from the sharp discharging edges 26 to the outer wall may be made greater than the distance I) from such edges to the inner wall.

In operation, the gases enter the outer end of the spiral gas passage 2 and pass inwardly through said passage in vortical or whirling fashion, thus causlng the suspended particles thereln to be sub ected to centrifugal action tending to force said particles outwardly with respect to-the gas and toward the outer wall of said passage. Simultaneously, the suspended particles are also subjected to the precipitating action due to the electric discharge and electrical field between the discharge electrodes and the collecting electrode surfaces. Since the discharge edges of the discharge electrodes are at a greater distance from the outer wall than from the inner wall and also because of the greater tendenc to outward discharge than to inward disc arge, and furthermore, by reason of a greater concentration of suspended particles in the outer portion of the gas stream by centrifugal action, the suspended partic es will be acted upon to a much greater extent by the relatively strong electrical precipitating action directed outward- I ly from the discharge electrodes to the outer wall than by the relatively weak electrical precipitating action directed inwardly toward the inner wall. The ap aratus, therefore, provides for maximum e ciency of utilization of the electrical energy in assisting the action of centrifu al force tending to drive the suspended articles toward the outer wall. The suspendedv particles will thus be largely deposited .upon the outer wall of the spiral gas passage, although some deposition may also occur on the inner wall due to inwardly directed electrical precipitating action. Furthermore,- some deposition may occur on the discharge electrode members themselves. The gas, eed of a large proportion of the suspended material originally contained therein, finally enters the central space 3 whence it is removed through outlet flue 7. The deposited discharge I v a source of electric current connected to said wall members and to said discharge electrode members and adaptedto maintain an electric discharge from said discharge electrode members, said discharge electrode members having portions of relativel sharp surface curvature at their outer'si es and having their inner sides of relativel gradual surface curvature and free from s arp discharging edges.

2. An apparatus as set forth in claim 1,

said discharge electrode members being mounted with said portions of relatively sharp surface curvature at a greater distance from the wall outside the gas passage than from the wall inside the gas passage-..

In testimony whereof I have hereunto subscribed my name this 21st day of August, 1930.

HEINRICH BERNHARD RUDER, 

